Spectral investigation of interaction of copper phthalocyanine with nitrogen dioxide

In this work, the determination of the products of interaction of NO2 molecules with copper phthalocyanine films was performed using IR and Raman spectroscopy. It was stated that on contact with π electron network of phthalocyanine the oxidizing NO2 gas causes the transfer of an electron from the phthalocyanine ring to NO2 molecule. The formation of [CuPc]+ and NO2− charged chemical forms was confirmed experimentally by Raman and IR spectroscopies, respectively. In order to determine the suggested structure of charge transfer complex the bands in the Raman spectra of CuPc film which are more sensitive to NO2 were assigned by means of measuring the isotopic shifts of corresponding modes upon 15N-substitution of β-CuPc. Besides, the correlation between sensor response, oxidative properties and structural features of CuPc film structure was demonstrated.